Low Lean Mass Linked to a 42 Percent Higher Risk of Death
Graded Moderate — an analysis of 49 observational studies with over a million people; such data cannot show cause, and results varied a lot between studies.
- Design
- Meta-analysis
- Participants
- 1,149,807
- Duration
- —
- Funding
- The authors report no funding.
Adults with little lean mass, mostly meaning little muscle, had a 42 percent higher risk of dying than those with a lot.
Body fat has been studied a lot. Less clear is what lean mass means for survival. Lean mass, or fat-free mass, is mostly muscle plus other non-fat tissue. A large analysis now puts a number on it: adults with little lean mass had a 42 percent higher risk of dying than those with a lot.
The researchers pooled 49 studies covering more than 1.1 million people. All lived at home, not in hospitals or care homes. Lean mass was measured in different ways, from X-ray scans to a weak electric current like that of body-fat scales to simply measuring the calf. The link was stronger in men than in women. It was clearest when calf size was the measure.
These are observations, not proof of cause and effect. There were signs that studies with weaker results were missing. After correcting for this, the risk was still 31 percent higher. When deaths in the first two years were left out, the link weakened and became uncertain. The authors say an illness that is just starting could shrink lean mass before it causes death.
Disclaimer: Research summaries are provided for informational purposes only and do not constitute medical advice. Always consult a qualified healthcare professional before making changes to your health routine.